Grinding-machine.



No.729,667. PATENTED JUNEZ,1903f" W. v. ROBINSONi GRINDING MACHINE.

APPLICATION FILED MAY 31, 1902. N0 MODEL. 2 SHEETS-SHEET 1 PATENTED JUNE2. 1.903.

w. v. ROBINSON. GRINDING MACHINE. APPLICATION FILED MAY 31, 1902.

no MODEL. 2 sums-imam UNITED STATES Patented June 2, 1903.

WILLIAM V. ROBINSON, OF DETROIT, MICHIGAN.

GRINDING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 729,667, dated. June 2,1903.

Application filed May 31, 1902.

tion, reference being had therein to the accompanying drawings.

The invention relates to grindin gmachiues, and is more particularlydesigned for use in the finishing of castingssuch, for example, asstove-plates.

It is the object of the invention to obtain a machine in which the Workof'finishing may be carried on automatically throughout the entireoperation and one which will enable a single unskilled attendant to turnout in the same time the work usually requiring a number of skilledartisans.

The invention consists first in the means employed for guiding thegrinder into operative relation to the work and in protecting the edgesand other unfinished portions of the work from said grinder.

More specifically, the invention consists in the peculiar constructionand arrangement of a marginal protecting-plate upon which the grinderbears before being fed onto the work and which prevents the edges ofsaid work from being injured by the grinder.

' The invention furtherconsists in the peculiar construction of theholders for the work during the grinding operation with which the workis adapted to be engaged withoutclamping and, further, in the peculiarconstruction, arrangement, and combination of parts, as hereinafterdescribed and claimed.

In the drawings, Figure 1 is a sectional perspective view ofthegrinding-inachine. Fig. 2 is a longitudinal section throu'ghtheguideway for the grinder-frame, showing. means of adjusting said framein relation thereto. Fig. 3 is a front elevation of the machine. Fig. 4is across-section through one of the holders, and Figs. 5, 6, 7, and 8illustrate modified forms of constructions of holders.

Generally described,the machine comprises an endless carrier A, adaptedtoffeed a series of work-holders B, which in their travel pass acrossthe path of one or more reciprocating grinders 0, said grinders beingmovable toward or from the work and being pressed in contact with theface of the work with a1im= ited tension. To permit of the free movementof said grinder toward and from the work, it is preferably carried by ajointed frame having a horizontalsection D and a vertical section E,said sections being pivotally connected to each other and the latterpivoted to stationary bearings, such as the hangers F. Movement isimparted to the grinderthrough the medium ofa drive-shaft G, journaledin the hangers F, and the belt connections H and I, respectively,connecting the shaft G with a counter-shaft J at the pivotal point ofthe frames D and E and said counter-shaft with the arbor of the grinderC. The grinder-frame may be reciprocated by any suitable mechanism suchas a pitman 'K, actuated by mechanism not shown.

The parts thus far described form no part of the present invention andmay be varied as desired, the only essential being that the rotarygrinder-wheel C be reciprocated across the path of the carrier and thatit be free to move toward 'or from the Work during its reciprocation.

In order to limit the movement of the grinder-wheel toward the work, aguide is preferably arranged, such as L, with which a portion, such asthe antifriction-roll L on the frame D, engages. This guide and rollwill prevent the grinder-wheel from moving downward beyond a certainlevel, but do not interfere with its upward movement, so that it is freeto ride over the raised'portions of the work. The grinder wheel ispressed downward with a limited pressure, which may be efiected by thegravity of the frame D, partially relieved by the counterweight M, saidweight being connected to one end of the lever M, while the opposite endthereof is connected by a link or chain M with the frame D. By adjustingthis counterweight any desired downward pressure maybe placed upon thegrinder O. The roll 'L' is preferably adj ustably secured to the frameD, as by the adjusting-screw L so that the limit of downward movement ofthe grinder may be varied. The guides L are secured to any suitablestationary support, such as the bar L I The castings which are to befinished by the machine usually vary greatly in form and present bothround and fiat surfaces, as well as unfinished projections which must beprotected from the action of the grinder. In order that the work may becarried on expeditiously, it is desirable that these castings may be fedto the machine in any order. This precludes the possibility of guidingthe grinder in relation to the face of the casting by any fixed cam, aseach separate casting would need a different form, and even if the areinjured by the grinder in passing on or oiffrom the casting. Moreover,with certain classes of work there would be danger of the wheel catchingupon the edges or projecting portions of the casting, so as to do injuryto either the casting orthe machine. 7 To overcome this difficulty,Ihave arranged protecting plates or strips. These are arranged upon thework-holders beyond the edges of the work and adjacent to any projectingportion of the work which must be protected. They are also preferablyformed of material which is harder than the castings to be ground.such,for instance, as chilled castiron. Thus the grinder will havecomparatively little abrasive action upon the protecting-strips incomparison with that produced on the casting to be finished. Byarranging these protecting-strips around the margin of the work, asindicated at N, they will also constitute a holder for the work whichsecures it from lateral movement while operated upon by the grinder.\Vhere the work is of irregular form, the holder therefor is formed witha supporting-bedNof similarshapeandtheprotecting-strips N are arrangedaround the margin, as shown in Figs. 1 and 4. Where the work is opencentrally,a protecting strip or plate,such as 0, Fig. 5, is placedtherein, and where a number of castings maybe fitted together in thesame holder they are provided with marginal protecting-plates, and, ifnecessary, intervening protecting-plates, such as P, Fig. 6.

. Again, where a projecting portion, such as a hinge-lug Q, Fig. 7,needs to be protected a plate or strip, such as R, is placed adjacentthereto, over which the grinder-Wheel will ride without injury to thelug Q.

In order that the finishing of the castings may be completed by oncepassing them through the machine, I preferably arrange a series ofgrinders C G, 850., each being provided with a jointed frame, thesections D of which are independently movable; but, if desired, thesections E may constitute a com mon frame and have a singlereciprocating device. The grinders O O, &c. may be graded according tothe nature of the work to be finished, so that the castings arerough-ground while passing the first grinders and are more highlyfinished by the later ones in the series. The employment of a series ofgrinders in this manner also permits of limiting the pressure of eachgrinder upon the work. Thus only a small amount of material is groundoff by each, which permits the wheel to more perfectly conform to theshape of the casting. Moreover, where the pressure of the grinder islight it will have but little effect on the marginal protecting-strip,which greatly lengthens the life thereof.

The marginal protecting-strips N are preferably of a form which tapersdownwardly toward the outer edge to the limit plane of downward movementof the grinders. Thus where the edges of the casting are some distanceabove this plane the grinding-wheel will mount up the incline of themarginal strip N, which will guide it onto the face of the casting.These marginal strips preferably conform to the shape of the edges ofthe casting; but this is not absolutely essential,as the edge of thecasting might be of irregular form and that of the protecting-stripstraight, as shown in Fig. 8. It is only necessary that the strip benear enough to the edge .of the casting'so that it will hold the wheelfrom injuring said edge.

The bed N of each holder preferably has a detachable engagement with thecarrier and may be held in relation thereto by suitable guides, such asS, upon the frame or bed T of the carrier. This construction. permitsthe attendant to first place the castings in engagement with each holderand then successively engage them with the carrier, by which they arefed through the machine, after which they are removed and new castingssubstituted for the finished ones. This detachable feature is not,however, absolutely necessary, as the castings might be dropped intoengagement with the holders at one end of the machine during themovement of the carrier and removed therefrom at the oppo site end.

What I claim as my invention is- 1. In a grinding-machine, thecombination with a'grinder adapted to be reciprocated across the surfaceof the work and yieldingly pressed in contact therewith, of a marginalguard surrounding the work upon which said grinder is adapted to ride atthe edge of the work to protect the latter from injury, said guard beingfashioned in conformity with the longitudinal vertical contour of theedge of the work.

2. In a grinding-machine, the combination with a work-carrier adapted tofeed a series of variable pieces of work, of a grinder having areciprocating movement across the path of said carrier and yieldinglypressed toward the surface of the work thereon, and 2. marginal. guardfor each piece of work on said carrier said guard surrounding the workand adapted to protect the edge thereof from in- ICC jury by saidgrinder, said guard being fashioned in conformity with the longitudinalvertical contour of the work.

3. In a grinding-machine, the combination of a work-carrier adapted tofeed a series of separated pieces of work, of variable surface contour,a grinder having a reciprocatory movement across the path of saidcarrier and yieldingly pressed toward the surface of the work thereon,means for limiting the inward movement of said grinder toward saidcarrier, said limit being below the lowest point in the surfaces to beground, and a marginal guard upon which said grinder is adapted to ridein entering upon each separate piece 01" the work, said guard beingadapted to guide said grinder into contact with the surface of the workand to protect the edges thereof from injury.

4. In a grinding-machine, the combination with a grinder adapted to bereciprocated across the surface of the. work and yieldingly pressed incontact therewith, of a guard upon which said grinder is adapted to rideprotecting a portion of the work from being ground, said guardconstituting part of the holding means for the work.

5. In a grinding-machine, the combination with a grinder having areciprocatory movement across the surface of the work and yieldinglypressed in contact therewith, of a holder recessed to receive the work,the marginal portions thereof forming guards upon which said grinder isadapted to ride on entering upon and leaving contact with said surfaceof the work, said marginal portion conforming to the vertical contour ofthe edge of the work and protecting the edges thereof from injury.

6. In a grinding-machine, the combination with a grinder adapted to bereciprocated across the surface ofthe work, of a guard upon which saidgrinder is adapted to ride, to protect a portion of the work from beingground, said guard constituting part of the holding means for the work.

7. In a grinding-machine, the combination with a grinder adapted to bereciprocated across the surface of the work, of a guard surrounding thework upon which said grinder is adapted to ride to protecta portion ofthe work from being ground, and means for yieldingly pressing saidgrinder into contact with the work.

8. In a grinding-machine, the combination with a grinder adapted to bereciprocated across the surface of the work, of a guard sun rounding thework upon which said grinder relieving the pressure of the grinder uponthe work. 9. In a grinding-machine, the combination with a grinderadapted to be reciprocated across the surface of the work, of a guardsurrounding the work upon which said grinder is adapted to ride toprotect a portion of the Work from being ground, and means whereby thegrinder may have a slight automatic vertical movement independent of itssupporting-frame.

In testimony whereof I affix my signature in presence of two witnesses.

WVILLIAM V. ROBINSON.

Witnesses:

HARRISON L. DAVIES, HARRY C. KENDALL.

